초록 ▼

A corrosion resistant coating for gas turbine engine includes a glassy ceramic matrix wherein the glassy matrix is silica-based, and includes corrosion resistant particles selected from refractory particles and non-refractory MCrAlX particles, and combinations thereof. The corrosion resistant partic

A corrosion resistant coating for gas turbine engine includes a glassy ceramic matrix wherein the glassy matrix is silica-based, and includes corrosion resistant particles selected from refractory particles and non-refractory MCrAlX particles, and combinations thereof. The corrosion resistant particles are substantially uniformly distributed within the matrix, and provide the coating with corrosion resistance. Importantly the coating of the present invention has a coefficient of thermal expansion (CTE) greater than that of alumina at engine operating temperatures. The CTE of the coating is sufficiently close to the substrate material such that the coating does not spall after frequent engine cycling at temperatures above 1200° F.

대표청구항 ▼

What is claimed is: 1. A corrosion resistant coating composition comprising: a binder free of hexavalent chromium, the binder comprising silicone, the binder comprising from about 5 to about 45 weight percent of the coating composition; a corrosion resistant particulate, the corrosion resistant par

What is claimed is: 1. A corrosion resistant coating composition comprising: a binder free of hexavalent chromium, the binder comprising silicone, the binder comprising from about 5 to about 45 weight percent of the coating composition; a corrosion resistant particulate, the corrosion resistant particulate comprising: a refractory particulate having a coefficient of thermal expansion greater than or equal to that of alumina as determined at a temperature of 1200° F., and a non-refractory particulate selected from the group consisting of FeAl, CoNiCrAlY, or combinations thereof, the corrosion resistant particulate comprising about 15 to about 92 percent by weight of the composition; and a non-aqueous solvent, the solvent comprising from about 3 to about 50 percent by weight of the composition, wherein the corrosion resistant coating has a coefficient of thermal expansion approximately that of an underlying superalloy substrate. 2. The coating composition of claim 1, wherein the refractory particulate is selected from the group consisting of alumina, zironcia, hafnia, yttria stabilized zirconia, yttria stabilized hafnia, ceria, chromia, magnesia, iron oxide, titania, yttria, and yttrium aluminum garnet, and combinations thereof. 3. The coating composition of claim 2, wherein the silicone binder comprises a siloxane. 4. The coating composition of claim 3, wherein the coating composition comprises from about 5 to about 45 weight percent binder, from about 3 to about 50 weight percent solvent, from about 10 to about 87 weight percent non-refractory particles, and from about 5 to about 82 weight percent refractory particles. 5. The coating composition of claim 4, wherein the non-refactory particulate comprises between about 5 to about 10 weight percent cobalt, about 25 to about 40 weight percent nickel, about 15 to about 25 weight percent chromium, about 5 to about 15 weight percent aluminum, and about 0.10 to about 1.5 weight percent yttrium. 6. The coating composition of claim 4, wherein the non-refactory particulate comprises between about 85 to about 95 weight percent iron, and between about 5 to about 15 weight percent aluminum. 7. A coated article comprised of a superalloy substrate and corrosion resistant coating, the article comprising: a superalloy substrate; and a coating composition applied directly to the superalloy substrate, the coating composition comprising, before curing and firing: a binder free of hexavalent chromium, the binder comprising silicone, the binder comprising from about 5 to about 45 weight percent of the composition; a corrosion resistant particulate, the corrosion resistant particulate further comprising: a refractory particulate having a coefficient of thermal expansion greater than or equal to that of alumina as determined at a temperature of 1200° F., and a non-refractory particulate selected from the group consisting of FeAl, CoNiCrAlY, or combinations thereof; the corrosion resistant particulate comprising about 15 to about 92 percent by weight of the composition; and a non-aqueous solvent, the solvent comprising from about 3 to about 50 percent by weight of the composition, wherein the corrosion resistant coating has a coefficient of thermal expansion approximately that of the superalloy substrate. 8. The coated article of claim 7, wherein the corrosion resistant particulate comprises alumina, zironcia, hafnia, yttria stabilized zirconia, yttria stabilized hafnia, ceria, chromia, magnesia, iron oxide, titania, yttria, and yttrium aluminum garnet, and combinations thereof 9. The coated article of claim 8, wherein the coating composition comprises from about 5 to about 45 weight percent binder, from about 3 to about 50 weight percent solvent, from about 10 to about 87 weight percent non-refractory particles, and from about 5 to about 82 weight percent refractory particles. 10. The coated article of claim 9, wherein the non-refractory particulate comprises between about 5 to about 10 weight percent cobalt, about 25 to about 40 weight percent nickel, about 15 to about 25 weight percent chromium, about 5 to about 15 weight percent aluminum, and about 0.10 to about 1.5 weight percent yttrium. 11. The coated article of claim 9, wherein the non-refractory particulate comprises between about 85 to about 95 weight percent iron, and between about 5 to about 15 weight percent aluminum. 12. A coated article comprised of a superalloy substrate and corrosion resistant coating, the article comprising: a superalloy substrate having an outer surface, the outer surface having a first corrosion resistant coating thereon, wherein the first corrosion resistant coating has a coefficient of thermal expansion approximately that of the superalloy substrate; and a coating composition overlying the first corrosion resistant coating, the coating composition comprising, before curing and firing: a binder free of hexavalent chromium, the binder comprising silicone, the binder comprising from about 5 to about 45 weight percent of the composition; a corrosion resistant particulate, the corrosion resistant particulate comprising: a refractory particulate having a coefficient of thermal expansion greater than or equal to that of alumina as determined at a temperature of 1200° F., and a non-refractory particulate selected from the group consisting of FeAl, CoNiCrAlY, or combinations thereof; the corrosion resistant particulate comprising about 15 to about 92 percent by weight of the composition; and a non-aqueous solvent, the solvent comprising from about 3 to about 50 percent by weight of the composition, wherein the coating composition has a coefficient of thermal expansion approximately that of the superalloy substrate. 13. The coated article of claim 12, wherein the first corrosion resistant coating is selected from the group consisting of MCrAlX coatings, aluminides, and noble metal-modified aluminides. 14. A coated article comprised of a superalloy substrate and corrosion resistant coating, the article comprising: a superalloy substrate; and a coating applied directly to the superalloy substrate, the coating comprising: a binder free of hexavalent chromium, the binder comprising silicone, the binder comprising from about 5 to about 75 weight percent of the coating; and a corrosion resistant particulate, the corrosion resistant particulate comprising: a refractory particulate having a coefficient of thermal expansion greater than or equal to that of alumina as determined at a temperature of 1200° F., and a non-refractory particulate selected from the group consisting of FeAl, CoNiCrAlY, or combinations thereof, the corrosion resistant particulate comprising about 25 to about 95 percent by weight of the coating, wherein the coating has a coefficient of thermal expansion approximately that of the superalloy substrate. 15. The coated article of claim 14, wherein the binder forms a glass matrix upon heating to a first preselected temperature and wherein the corrosion resistant particles are substantially uniformly distributed in the matrix. 16. The coated article of claim 15, wherein the binder forms a glassy ceramic matrix upon heating to a second preselected temperature, the second preselected temperature being greater than the first preselected temperature. 17. A coated article comprised of a superalloy substrate and corrosion resistant coating, the article comprising: a superalloy substrate having an outer surface, the outer surface having a first corrosion resistant coating thereon, wherein the first corrosion resistant coating has a coefficient of thermal expansion approximately that of the superalloy substrate; and a second coating overlying the first corrosion resistant coating, the second coating comprising: a binder free of hexavalent chromium, the binder comprising silicone, the binder comprising from about 5 to about 75 weight percent of the second coating; and a corrosion resistant particulate, the corrosion resistant particulate comprising: a refractory particulate having a coefficient of thermal expansion greater than or equal to that of alumina as determined at a temperature of 1200° F., and a non-refractory particulate selected from the group consisting of FeAl, CoNiCrAlY, or combinations thereof, the corrosion resistant particulate comprising about 25 to about 95 percent by weight of the second coating, wherein the second coating has a coefficient of thermal expansion approximately that of the superalloy substrate. 18. The coated article of claim 17, wherein the binder forms a glass matrix upon heating to a first preselected temperature and wherein the corrosion resistant particles are substantially uniformly distributed in the matrix. 19. The coated article of claim 18, wherein the binder forms a glassy ceramic matrix upon heating to a second preselected temperature, the second preselected temperature being greater than the first preselected temperature.